Metropoulos Forum

hi everyone,

i'm thinking of modding my stock 100 watt kit.
into the BOG territory, i'd like to try some mullard preamp tubes ( don't know wich one would be the best ) , and some 6550. Tung sol ? NOS ? from when ?

And, i'm discovering this idea of shared or split cathode, the history of this modification over the time, and the use of this by Jimi Hendrix.
So now i'd like to try the shared cathode, but i wonder if i could simply install a switch to let me change for what i like. I don't know the limits of this mod, if it needs some other changes arround that, that would/could be switchable too ( the amp on standbye or off i guess, not on ? ).

i'd like to try the superlead/bass mod with some switchs too.

and i'd like to put some NOS mustard caps now, as everyone seems to love it. now i have sozo.

i don't know yet what all this could look like, in a schematic, or in some pictures.

i don't even know what i should change , if i go from el34 to 6550.

i'd like to try the mods , and some important configurations of the jimi hendrix amp at amparchive ; )

thanks for your attention. if you have some ideas and some nice help, feel free ! ; )
Adrien

doing a split to shared switch is easy I think someone here has a pic. Probably SDM...Ill go look see if I have one

cool, thanks.
i wonder if it's switchable while the amp is on, just like switching from an effect to another one.
i'm a beginner you know ...

and i wonder, other than doing it according to a preference, wich components should be nice to change for some others. Like : changing the stock resistors to some NOS carbon film resistors, changing the stock sozo caps to some NOS mustard caps ... you know ... what else could i change this way ? the cathodes too ?
i suppose that i should change the stock metroamp c1998 dagnall standard transformer for a metroamp c1998 dagnall vintage. what else could be very cool to change ?

I asked that question a while ago, basic answer was you'll get a pop. And this isn't good thing because while switching you cathode wouldn't be grounded, best to switch to stand by then change it.

rip

I figure this might work

Thanks a lot for the help.
i'll try to understand what it means. But on wich amp did you base your drawing ?
i'm trying to make a parrallel between this drawing, and the one of my amp, 69 superlead.
thx
Adrien

its valid regardelss. If you understand what he drew it doesant matter what amp or circuit etc. it works wire it up

actually it looks dead on the same.

It is the switch on the left that concerns you (the one on the right brings the V2a bypass cap in and out (the one for upper mids boost on a Superlead).

Very simple and easy to do, really fattens the sound up. particularly with single coils on an upside down big headstock white strat

Cool, I've been looking for that switching. Since I built the amp (69) it's been shared and without the V2a bypass cap. Really nice warm but still raucous sound. Decided to go to split and put the bypass cap in and it really came on fire. I still like the other way though as well, especially for more bluesy/classic stuff.

Would you guys recommend the switches being in the back to minimize wire length or is there a good placement for the switches and more so the wires for the front?

What's the proper name for the switches when trying to find one. dpdt? They're basically on/on switches right?

They're actually just spdt switches.

I put them there to keep wires short and out of the way (on the top of the chassis) I don't need to be switching them often, and because of the popping issues figured I'd set them and leave them as soon as I figure how I like the sound.

Rip

Not to stir the pot but I'm just curious as to why some people prefer the shared cathode tone over the split cathode arrangement? To me, anything shared cathode has a bit of "sloppy-ness" and farty lows and no tightness/definition/clarity to speak of. Just curious as to how anyone can play through that?

I don't mean to be irritating by reviving an old thread but I think I'm going to do this modification to my '74 SL this weekend. It has a polarity switch, but I was wondering if this would be the right kind of switch I would need for the above-mentioned modification.

I'm not sure, but do you know what type of switch it is? SPST DPST DPDT?

Rip